Soviet engineer Nikolai Alekseenko created a project for a walking "invulnerable" bunker. Alekseenko's design provided for anti-cannon armor, as a result, the vehicle had to weigh more than 45 tons - only the frontal armor had a thickness of 200 millimeters. In theory, not a single sample of German artillery could penetrate this.
The bunker was equipped with a 76-mm cannon, apparently the engineer planned to put an L-17 in it. Two machine guns on the sides of the main gun were supposed to protect against a possible attack. And what is most interesting, according to Alekseev's idea, the bunker was supposed to walk on its own, though at a speed of only 2 km / h.